Radio reception apparatus



- Jan. 12 19260 1,569,446

T. E. ARUNDEL.

RADIO RECEPTI ON APPARATUS Filed March 12 1925 ma ma as 2: FigsT.E.Arundel Patented Jan. 12, 1926.

UNITED STATES PATENT OFFICE.

THOMAS E. ARUNDEL, OF OliIAI-IA, NEBRASKA. ASSIGNOR OF THIRTY-SEVEN ANDONE-HALF PER CENT TO GUY D. SHEPHERD AND TWENTY-FIVE PERI CENT TOWILLIAM H. METCALFE, BOTH OF QIviAI-IA, NEBRASKA.

RADIO nnonrrron AQPPARATUS.

Application filed March 12, 1925.

To all whom it may concern.-

Be it known that I, TrioM-iis l9. AiiUNimL, a citizen of the UnitedStates, residing at Omaha, in the county of Douglas and State ofNebraska, have invented certain new and useful Improvements in Radioiteception Apparatus, of which the following is a specification.

The present invention relates to radio reception apparatus and moreparticularly to devices which are known as detectors.

An object of this invention is to provide a detector which is of apermanent nature, but which is adapted to replace crystals and the likeheretofore used and at the same time to obtain the clearness andintensity of reception which is paramount to, or even greater than themost efiicient crystal receivers at present known. I

Another object of the invention is to provide a detector having avariable or adjustable contact surface comprising an infinitesimalnumber of contact or detector points so relatively positioned that butslight adjustment between the surfaces is necessary to renew or changethe relation between the contacts and thus is insured at all adjustmentsat least only or a few loud or clear points of contact.

A further object of the invention is to provide a detector havingeomplemental surfaces adapted to be brought into proper cont-actingpositions and which may have abrasions or roughened surfaces arrangedpromiscuously on said surfaces so that variable and unpredeterminedcontacts may be made during the relative movements of the surfaces toinsure new combinations of con tacts for effecting the desired results.

A still further object of the invention is to provide means for renewingor increasing these contact surfaces so that upon wear or grinding downof the surfaces the same may be renewed by the relative adjustment ofthe same incident to the abrading action.

The invention still provides a substance of an abrasive or granularnature pocketed between the relatively movable surfaces of the detectoradapted to cut and abrade the surfaces irregularly so as to cause theirregular projections or' depressions osse .ial to the fori'nation ofthe enumerable contact points desired.

Serial No. 14,922.

With the foregoing and other objects in view, the invention will be morefully described hereinafter, and will be more particularly pointed outin the claims appended hereto.

In the drawings, wherein like symbols refer to like or correspondingparts throughout the several views.

Figure l is a sectional view through a detector constructed according tothe present invention and mounted on the'panel board, a fragment of thelatter being shown.

Figure 2 is a detail sectional View through the detector removed fromthe panel board and socket.

Figure is a side elevation of the same.

Figure 4 is an inner end elevation of the detector.

Figure 5 is an outer end elevation of the same, the thumb piece beingremoved.

Figure 6 is a detail face view of the fixed element of the detector,showing on a greatly enlarged scale the particles or roughenedsurfacesof the element.

Figure 7 isa graphic illustration, greatly enlarged of the abrasiveparticles which may be used, showing the irregular contours of the samefor cutting irregularly intothe adjacent contact surfaces of thedetector, and

Figure 8 is a detail face view of the movable or adjustable element ofthe detector, showing the projections or serrations on its face.

Referring to the drawing, 10 designates a panel board or the like ofusual construction and upon which is mounted a tubular socket 11 bymeans of bolts 12. The socket 11 is of a common well known type andprovided with an outstanding annular flange 13 at its inner end' andthrough which the bolts 12 are adapted to pass, the bolts carrying nutsin the ordinary manner for clamping the socket against the panel board10 and about an opening 14 which is formed through the panel.

The flange 123 carries at preferably diametrically opposejd points apair of inwardly extending spring arms 14: and 15 which may be of flatspring metal and having their inner ends overturned upon themselves toform spring contacts 16 which are normally urged forwardly in the socket11 toward the panel board 10. The socket 11 is provided in one side andin its inner wall with a bayonet slot or groove 17 in the usual mannerfor facilitating the locking or retention of an electrical device in thesocket.

Applicant takes advantage of this stock form of socket for the supportand mounting of his detector and with such purpose in view has inventeda detector which comprises a cylindrical block 18 adapted to freely fitwithin the socket l1 and which at its outer side is elongated to providea supporting sleeve 19 through which is rotatably and slidably mounted astem 20 carrying a thumb piece 21 on its outer end which is threaded orotherwise suitably secured to the stem 20 and by means of which the stem20 may be rotated, oscillated or moved in and out through the sleeve 19.The cylindrical plug 18 is recessed at its inner side to provide adetector chamber 22 and in which is positioned a substantiallysemi-globular head 23 mounted on the inner end of the stem 20. Fittingin the detector chamber 22 and preferably toward the inner end of theblock 18 is a fixed element 24 of the detector which may be of anysuitable material and which is frictionally heldm the cavity and insuitably spaced relation from the head 23 which constitutes the otherdetector element.

The inner face of the detector element 24 is concaved to at leastpartially conform to the spherical or globular configuration of the head23 and to thus affect not only a relatively wide area of possiblesurface contact between the elements of the detector but to also providea pocket or enclosure between the members for receiving and holding aquantity of abrasive particles 26 which may be carborundum or any othersuitable substance comprising fine particles capable of abrading orcutting into the adjacent surfaces of the detector elements 23 and 24.These particles 26 will dig into the surfaces of the elements and cutand lift the same in uneven projections so that the surfaces, under thecutting action of the particles 26 will be formed in the rough contactbodies comprising enumerable projections which differ in length and sizeand which are irregularly positioned in the surfaces so that mymanipulation of the head 23 different combinations of contacts may beformed and thus a continued and new adjustment of the detector may behad.

The abrasive particles 26 are enclosed in the chamber 22 and cannotescape from the plug 18 as the inner or fixed detector element 24 isfrictionally held in place. In order to provide a contact between thefixed element 24 to hold the element firmly in position, a contact screw27 is threaded into the inner side of the block 18 in position tooverlap the marginal portion of its head against the rear side of theelement 24. This provides a contact 27 which is adapted to be broughtopposite the spring contact 16 of the spring arm 15. The stem 20 is inelectrical communication with a conductor strip 28 arranged in thesleeve 19 to bear against one side of the stem 20 and which is carriedupwardly through the sleeve 19 and block 18 to a second contact screw 29which has an enlarged head lying against the inner end of the plug 18.In this case, however, the contact screw 29 may be arranged so as tomaintain its head out of line with the fixed electrode 24. The head ofthe contact screw 29 is mounted on the plug or block 18 in such positionthat when the latter is inserted in the socket l1 and properlypositioned the head of the contact screw 29 will engage the springcontact 16 of the arm 14 and establish electrical connnunication betweenthe arm 14 and the conductor strip 28. The plug or block 18 provided atone side with a locking pin 30 which projects radially from the blockand is adapted to enter the bayonet slot 17 for not only determining theproper positions of the contact screws 27 and 29 but to also hold theblock or plug in the socket 11 against the tension of the spring arms14- and 15. The spring arms 14 and 15 are connected to ground andantenna wires respectively with the suitable interposedinstrun'ientalities or mechanism for receiving the transmittedvibrations.

The spring arms 14 and 15 may be secured in any suitable manner upon thesocket flange 13 such as by screws 31 as shown and equipped withthreaded sockets embedded in the rear side of the sockets. It is evidentthat the conductor strip 28 forms a connection with the stem 20 and head23 so that the magnetic current may pass between the elements orelectrodes 23 and 24 of the detector and the desired resistance providedby the imperfect contacts between raised or roughened surfaces of theelements and by the intercepting abrasive particles 26. From time totime the thumb piece 21 may be manipulated to disturb the relationbetween the electrodes 23 and 24 so as not only to grind one against theother with the intercepted particles 26 but also to reestablish thenecessary electrical communication between the elements which isessential to maintain the detector in its ellicient adjustment.

After the electrodes or elements have been properly adjusted suchadjustment will be rigidly maintained on account of the adj ustmentbeing effected through the relatively large electrodes 23 and 21-because the stem 20 is frictionally held in the sleeve 19 by the springaction of the conductor strip 28. These large electrodes 23 and 21 willthus maintain the smaller particles in proper contact and prevent theirdisturbance incident to vibration or jarring of the device.

Of course either one or both surfaces of ,1 the electrodes or elements23 and 2st may be roughened so as to produce the projections from itssurface, Figure 1 showing on a greatly enlarged scale the projections 32carried upon the spherical surface of the head 23. Of course theelectrodes 23 and 2% is an improvement on the construction disclosed inmy co-pending application Serial No. 715,959, filed May 26, 192&, andwhich was allowed September 15, 1924.

I do not wish to be restricted to the size, form, and proportions of thevarious parts, and obviously changes could be made in the constructionherein described without departing from the spirit of the invention, it

being only necessary that such changes fall within the scope of theappended claims.

hat is claimed is 1. A detector for radio reception comprising a pair ofrelatively movable electrodes, and abrasive particles interposed betweenthe electrodes for roughening the contact surfaces of the same.

2. In a detector, a block, a rotatable electrode mounted in the block, asecond electrode mounted in the block interposed for electricalcommunication with the first electrode, and a surface rougheningsubstance arranged for contact with the electrode by manipulation of oneof the electrodes to roughen the surface of the same.

A detector for radio reception comprising a block, a fixed electrodemounted in the block, a movable electrode mounted in the block, saidblock being chambered about said electrode, and a quantity of abrasiveparticles enclosed in said chamber for engagement between and about theelectrode for cutting the opposed faces of the same when the movableelectrode is manipulated.

In testimony whereof, I have aflixed my signature.

THOMAS E. ARUNDEL.

